Figure 3: Effect of PLGA particles on the viability of IEC-6 (a) and U-937 cells (b). PLGA particles were incorporated with PBS. Both cell types were treated with different concentrations of PLGA particles (0 to 250 μg/mL) for up to 7 days. Cell viability was then determined by using the MTT assay. The data are expressed in terms of the percentage of viable cells relative to control cells, which were treated with medium only.